In healthcare facilities, patients who are critically ill, weak, or comatose may be unable to chew their food. For such patients, nourishment may be provided with a nutritional liquid using a conventional enteral feeding process. Enteral feeding can be conducted using a variety of techniques. One technique utilizes a nasogastric tube which is inserted through the patient's nasal cavity and into the patient's gastrointestinal tract. The exterior end of the tube can be fluidly connected to a container of an enteral nutritional product. A second technique utilizes a gastrostomy or jejunostomy tube which is inserted through the patient's abdominal wall directly into the patient's gastrointestinal tract. Here again, the exterior end of the tube can be fluidly connected to a container of an enteral nutritional product.
U.S. Pat. No. 4,934,545 discloses one conventional container for an enteral nutritional product. The container includes an opening that is initially closed with a seal which is typically a foil membrane or thin plastic membrane. An adaptor cap is threaded onto the end of the container over the membrane seal. The adaptor cap includes a spike port which is initially occluded with a frangible membrane that is unitary with the cap and that can be pierced or broken away as the spike is inserted through the port. The spike is inserted through the port frangible membrane and is inserted further to also pierce the foil or plastic membrane which initially seals the container opening. The adaptor cap also includes a vent aperture and a microbial filter across the vent aperture for admitting air to facilitate draining of the bottle.
Typically, a plurality of such containers (with the adaptor caps mounted thereon) are packed in a corrugated carton for shipping and storage. The cartons may be stacked one on top of the other, and this subjects the containers to vertical loading. In order to protect the adaptor cap, a separate overcap or dome piece is mounted on the top of the adaptor cap. The overcap or dome piece has a generally flat exterior surface for accommodating vertical loading. The overcap or dome piece also serves as a barrier against contaminant ingress. The overcap or dome piece must also present a sufficiently large, upwardly facing, flat surface to distribute the force and prevent the overcap from puncturing the top of the carton.
One such conventional overcap or dome piece is illustrated in the U.S. Pat. No. Des. 330,332, and the overcap or dome piece is shown in that patent mounted to the top of an adaptor cap. Although such an overcap or dome piece functions generally satisfactorily, it would be desirable to provide an improved system which would accommodate more economical manufacture. Further, it would be advantageous if such an improved system could provide an enhanced barrier against contaminant ingress.
Typically, the overcap or dome piece is designed to be snap-fit onto the adaptor cap. This requires relatively close molding tolerances which increase the manufacturing cost. It would be desirable to provide an improved system which could be manufactured with greater tolerances and at less cost while providing the same or superior functionality.
When a healthcare facility uses a container having an adaptor cap and overcap assembly as illustrated in the U.S. Pat. No. Des. 330,332, a healthcare professional must initially remove the separate overcap to expose the adaptor cap. The overcap, which is a rigid, thermoplastic molded structure, then becomes a significant waste material requiring disposal. It would be desirable to provide an improved adaptor cap system which could substantially minimize, if not altogether eliminate, the requirement to remove and dispose of a separate, rigid plastic overcap.
The conventional adaptor cap and overcap assembly illustrated in the U.S. Pat. No. Des. 330,332 includes a pierceable membrane recessed within, and across, the spike port. While such a design functions satisfactorily, it would be desirable to provide an improved design which would permit easier insertion of the spike while at the same time providing enhanced spike retention. Further, it would be advantageous to provide a system which would provide an enhanced contaminant barrier for the exterior portion of the spike port and for the exterior portion of the adaptor cap around the filter.
The prior art filter employed in the design illustrated in U.S. Pat. No. Des. 330,332 must be initially retained in a holder by staking, and then the filter holder must be pressed into the adaptor cap. While this assembly functions satisfactorily, it would be desirable to provide a less complex and less costly filter retention system.
The conventional adaptor cap illustrated in the U.S. Pat. No. Des. 330,332 includes a separate, annular rubber or plastic gasket for sealing against the top of the container. It would be advantageous if an improved adaptor cap could be provided with an enhanced gasket system which, inter alia, would not require the handling and assembly of a separate gasket during manufacture.
Finally, it would be desirable to provide an improved, user-friendly, system for exposing the adaptor cap spike port and vent aperture just prior to insertion of the spike. Further, it would also be advantageous to provide such a system with a tamper-evident feature that would clearly alert the healthcare professional to a condition in which the contaminant ingress barrier seal has been breached.
The present invention provides an improved adaptor cap which can accommodate designs having the above-discussed benefits and features.